This implements the comparator and orders search results
alphanumerically by ID. Normally called like this:
private Engine searchEngine = new net.sourceforge.nite.search.Engine();
reslist = searchEngine.search(nom, "($a segment)");
reslist.remove(0);
Collections.sort(reslist, new SearchResultIDComparator());
The first element of a search result list is always a list of
variable names and that's why we normally remove it before passing
to the Comparator. Note that this comparator does traverse along
the result and into any subqueries to distinguish results where the
first element is the same.